package beike;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 * @author zhangmin
 * @create 2022-03-21 18:38
 */
public class Main1 {
    public static void main(String[] args) {
        Scanner cin=new Scanner(System.in);
        int n=cin.nextInt();
        cin.nextLine();
        char[] line=cin.nextLine().toCharArray();
        int[][] va=new int[n][n];
        int res=Integer.MIN_VALUE;
        for (int i = 0; i < n; i++) {
            for (int j = i+1; j < n; j++) {

            }
        }
        System.out.println(res);
    }
}
